Internal combustion engine



June 24, 1941. STEINER 2,246,701

INTERNAL COMBUSTION ENGINE Filed Feb. 4, 1959 3 H II Hill 1L L J Z? 26 .H:| IIHIH llll llllll INVENTOR li /v.5 firs/NEE.

Patented June 24,1941

NT OFFICE nv'ranmu. COMBUSTION ENGINE Hans Steiner, Winterthur, Switzerland, assignor t Anonyme, Winterthur,

to Sulzer Freres, Soci Switzerland Application February 4, 1939, Serial No. 254,552

In Switzerland February 8,193 8' 7 Claims.

This invention relates to improvements in reciprocating internal combustion engines, more particularly to fuel pump and injection means for such engines.

In a reciprocating piston internal combustion engine having pressure responsive fuel pump means the pressure chamber of which is connected to a working cylinder of the internal combustion engine so that the fuel pump is actuated by the compression or combustion pressure in said working cylinder, according to the present invention, means are provided whereby the pressure chamber of the fuel pump piston member is scavenged, at least periodically, by air or inert gas. 1

Preferably the arrangement is such that the passage connecting the pressure chamber of the fuel pump means and the working cylinder is also scavenged by air or inert gas.

The air or inert gas for scavenging the pressure chamber of the fuel pumppiston member is preferably admitted on eachpiston stroke in the internal combustion engine cylinder. The connection between the pressure chamber of the fuel pump means and the valve for admitting the scavenging air or inert gas to the pressure cham ber which valve may be operated mechanically or by gas pressure, may be such that an eddying or whirling scavenging movement of the air or inert gas is produced in the pressure chamber.

Thus, the present invention tends to prevent the interior of the pressure chamber of the fuel pump including the surface of the piston member as well as the passage connecting the 'said pressure chamber and the working cylinder, in case this passage is also to be scavenged, from being fouled, for example by carbon, because the scavenging action minimizes settling of soot and carbon on the surfaces of these parts.

Further and. other objects of the present invention will be apparent from the accompanying specification and claims.

An embodiment of the present invention is illustrated diagrammatically by way of example in the accompanying drawing as applied to an internal combustion engineoperating as an air compressor in which the fuel pump of the internal combustion engine is operated by the compression pressure in the working cylinder of said engine.

. In the accompanying drawing- Figure 1 is a diagrammatic part-sectional view of a plant according to the present invention;

Figure 2 is a sectional view taken along line II--II of Figure 1.

In the construction illustrated, the engine comprises oppositely moving pistons I and 2-operating in a common working cylindert, the combustion chamber 6 of which is'conflned by the piston faces 4 and 5, and a fuel injection device 1 controlled by a fuel valve 8 for injecting fuel into the'combustion chamber 6. The pistons l and 2 are of the truncated type, and their outer faces 9 and iii are adapted to compress air in air compressioncylinders II and IZ-respectively, whereby the annular chambers l3 and I4 may act as dashpots or buffers for checking the inward movement of the pistons.

The air compression cylinders provided with air inlet valves i5 and i6 respectively through which valves air is drawn, and with delivery valves H. and I8 respectively, through which valves air is delivered to the delivery pipe l9 and thence through inletports 2| into the working chamber 6 of the internal combustion engine. The combustion gases are discharged through ports 20 from which these gases may be delivered, for example, to a gas turbine which is not shown.

The valve 8 of the fuel injection device 1 is so loaded by a spring 22 that this valve will only open when the pressure of fuel in the delivery chamber 23 of the fuel injection device exceeds; a predetermined value, and will close immediately when the pressure in chamber 23 falls below this value.

Fuel is delivered to the injection device 1 by means of fuel pump 25 which draws fuel through check valve 28 from intake pipe 2'! to which fuel is delivered under pressure and delivers it through a delivery valve 29 to the delivery chamber 23 of the fuel injection device I; the piston of the fuel pump 25 is adapted to be operated by a piston member 24. The face of the piston member 24 is exposed to the pressure in the working chamber 6 of the internal combustion engine, with which it is connected by means, of conduit or passage 26.

Thus, the pressure in the working chamber 6 acts through the pipe 26 on the piston member 24 to cause delivery of fuel by the fuel pump 25 at the appropriate time, the ratio between the pressure in the working chamber 6 and the pressure at which fuel is delivered being determined by the ratio of the areas of the piston member 24 and of the plunger of the fuel pump 25. Fuel is supplied under pressure to pump 25 through conduit 21. Whenever the pressure in conduit 25 is below a predetermined value piston 24 rises, because of the fuel pressure, and the fuel chamber below piston 24 is refilled.

ll and l2 are Means are provided for periodically scavenging with pure air or inert gas the pressure chamber above the fuel pump piston member 24 and the passage 26 by which this pressure chamber communicates with the working chamber 6. The pressure chamber above the pressure responsive fuel pump member 24 communicates through a pipe 32 with a valve 3| which admits air or inert gas under pressure from a pipe 30 so that this air or gas blows through the pipes 32 and 26 and through the pressure chamber above the piston member 24 as soon as the scavenging period of the working chamber 6 starts. Opening of the valve 3| may be efiected automatically during the scavenging period of the working chamber 6 by constructing the valve 3| as a non-return valve and maintaining the pressure in the pipe 30, for example, by means of a pump 33, slightly higher than the scavenging pressure in the working chamber 6.

The passage 32 may be so arranged in relation to the pressure chamber above the piston member 24 that the flow of air or inert gas through the passage 32 produces in the chamber above the piston member an eddying or whirling scavenging motion of the air or inert gas.

It is obvious that if the air or inert gas delivered through the pipe 30 is cold, it will not only tend to keep the passage 26 and the pressure chamber above the piston member 24 free from dirt but will also tend to cool these parts.

While I believe the above described embodiments of my invention to be preferred embodiments, I wish it to be understood that I do not desire to be limited to the exact details of design and construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

1. In an internal combustion engine, a combustion cylinder, pressure responsive fuel pump means connected with the interior of and operated by the pressure prevailing in said combustion cylinder, and scavenging means connected with said fuel pump means for scavenging the interior of said pressure responsive means.

2. In an internal combustion engine, a combustion cylinder, pressure responsive fuel pump means comprising a pressure chamber connected with the interior of said combustion cylinder, and scavenging means connected with said pressure chamber for scavenging the interior thereof.

3. In an internal combustion engine, a combustion cylinder, pressure responsive fuel pump means comprising a pressure chamber, a conduit connecting the interior of said cylinder and said chamber, and scavenging means connected with said conduit and said pressure chamber for scavenging said conduit and said chamber.

4. In an internal combustion engine, a combustion cylinder,' a piston operating in said cylinder, pressure responsive control means connected with and being responsive to the pressure prevailing in said combustion cylinder, and scavenging means connected with said pressure responsive means for scavenging the interior thereof, said scavenging means comprising a control means responsive to the position of said piston.

5. In an internal combustion engine, a combustion cylinder, pressure responsive fuel pump means connected with and responsive to the pressure prevailing in said combustion cylinder, and scavenging means connected with said pressure responsive means for scavenging the interior thereof, said scavenging means comprising a pressure responsive control means operatively connected with and responsive to the pressure prevailing in said first mentioned pressure responsive means.

6. In aninternal combustion engine, a combustion cylinder, pressure responsive fuel pump means connected with and responsive to the pressure prevailing in said combustion cylinder, and scavenging means connected with said pressure responsive means for scavenging the interior thereof, said scavenging means comprising a pressure responsive scavenging matter intake check valve operatively connected with and responsive to the pressure prevailing in said pressure responsive means and affording admission of scavenging matter into said pressure responsive means whenever the pressure therein is below a predetermined value.

7. In an internal combustion engine, a combustion cylinder, pressure responsive fuel pump means connected with and responsive to the pressure prevailing in said combustion cylinder, and scavenging matter supply means connected with and adapted to supply scavenging matter to said pressure responsive means for scavenging the interior thereof.

HANS STEHNER. 

